Organic semiconductors and organic/inorganic hybrid semiconductors are expected to be applied to photoelectric conversion devices such as a photovoltaic, a light emitting element, and a photosensor. Using these semiconductors as, for example, forming materials of active layers of photoelectric conversion devices such as a photovoltaic makes it possible to employ an inexpensive coating method for forming the active layers and the like, and thus enables a great reduction in a formation cost of the active layers and the like. Because of this, an organic photovoltaic and an organic/inorganic hybrid photovoltaic are expected as next-generation photovoltaics that cost low and are harmless.
Cells forming a photovoltaic module each have a structure in which an active layer is sandwiched by a transparent electrode and a counter electrode. As the transparent electrode, a transparent conductive oxide not having sufficient conductivity is typically used, and accordingly, as the area of the cell increases, efficiency for extracting generated electric charges to the outside deteriorates more. To solve this, a plurality of strip-shaped cells are formed side by side and the plural cells are connected in series. A series photovoltaic module having the plural cells is formed by the following method, for instance. Transparent electrodes of the respective cells are formed on a transparent substrate. An active layer is formed on the whole surface of the plural transparent electrodes by coating. Parts of the active layer are scribed, whereby grooves from which the transparent electrodes are exposed are formed. Counter electrodes are formed on the active layer having the scribe grooves so as to correspond to the respective cells. At this time, in the scribe groove, the counter electrode of the adjacent cell is filled, so that the counter electrode of the adjacent cell is electrically connected with the transparent electrode exposed to the inside of the scribe groove.
The scribing of the active layer is executed by mechanical scribing using a cutting tool or laser scribing using laser light, for instance. The hard transparent conductive oxide layer exists under the soft, viscous, and low-brittleness active layer, and thus at the time of scribing the active layer, the active layer is likely to remain in the scribe grooves and on the conductive metal oxide. The active layer, if remaining, increases electrical resistance between the counter electrode of the adjacent cell and the transparent electrode, resulting in deterioration of power conversion efficiency. Increasing a scribing pressure or output power of laser in order to prevent the active layer from remaining is likely to cause a crack or the like in the transparent conductive oxide layer. In a case where the substrate as the base of the transparent conductive oxide layer is a soft substrate such as a resin substrate, the increase in the pressure especially at the time of the mechanical scribing causes the soft substrate to deform by being pushed by a cutting tool, which is more likely to cause a crack in the transparent conductive oxide layer.
In order to prevent the crack of the transparent conductive oxide layer while reducing the remaining of the active layer at the time of the scribing, studies are being made on forming a conductive layer under part of the active layer that is to be scribed and scribing the active layer together with a thickness-direction part of the conductive layer. Since the thickness-direction part of the conductive layer which is easy to scribe is scribed together with the active layer, it is possible to reduce the remaining of the active layer. Further, since the easiness of scribe of the active layer is enhanced, it is possible to reduce, for example, a load of an excessive pressure to the transparent conductive oxide layer. However, if part of the conductive layer is, for example, mechanically scribed, cutting chips of the conductive layer produced at the time of the scribing may become the residue in the periphery. Such cutting chips of a conductive substance cause a short circuit or the like between the cells. The above circumstances have given rise to a demand for an art to improve electrical connectivity between the adjacent cells (photoelectric conversion parts) by achieving both the reduction of the remaining of the active layer on the transparent electrodes and the prevention of breakage of the transparent electrodes and by inhibiting a short circuit or the like between the cells due to the cutting chips of the conductive substance, at the time of the scribing of the active layer.